Generic Name levofloxacin =

     Manufacturer Ortho-McNeil =

     Treatment Class Anti-infective =

     Indication Respiratory, skin, and upper and lower urinary tract infect=
ions =



Antibiotic Levofloxacin
                                        Approved

                             Reprinted from the January/February 1997 issue=
 of =

                           Medical Sciences Bulletin [Med Sci Bull. 1997; 2=
0(6)] =



                     The fluoroquinolone antibiotic levofloxacin (Levaquin/=
Ortho-McNeil)
                     has received FDA approval for respiratory, skin, and u=
pper and lower
                     urinary tract infections. Levofloxacin is the active l=
-isomer of Ortho's
quinolone ofloxacin (Floxin); isolating the pure l-isomer from the
                     racemic mixture of d- and l- rotatory isomers gives a =
compound with
                     enhanced efficacy, improved tolerability, and a longer=
 duration of action.
                     As with other quinolones, levofloxacin inhibits bacter=
ial growth and
                     reproduction by blocking the enzyme DNA gyrase. The an=
tibiotic is
                     active against gram- positive organisms (Enterococcus =
faecalis,
                     Staphylococcus aureus, Streptococcus pneumoniae, and
                     Streptococcus pyogenes), gram-negative organisms (Ente=
robacter
                     cloacae, Escherichia coli, Haemophilus influenzae and =
Haemophilus
                     parainfluenzae, Klebsiella pneumoniae, Legionella pneu=
mophila,
                     Moraxella catarrhalis, Proteus mirabilis, and Pseudomo=
nas
                     aeruginosa), and other atypical pathogens (Chlamydia p=
neumoniae
and Mycoplasma pneumoniae). =


                     Levofloxacin is indicated for acute maxillary sinusiti=
s, acute bacterial
                     exacerbation of chronic bronchitis, community-acquired=
 pneumonia,
                     uncomplicated skin and skin structure infections, comp=
licated urinary
                     tract infections, acute pyelonephritis, cystitis, pros=
tatitis, and sexually
                     transmitted disease (urethral and cervical gonorrhea, =
nongonococcal
                     urethritis and cervicitis, and mixed infections of the=
 urethra and cervix). In
                     two clinical studies of patients with respiratory infe=
ction (total: 854
                     patients), levofloxacin 500 mg orally or intravenously=
 (IV) once daily for
                     7 to 14 days showed clinical success rates (cure plus =
improvement) of
                     93% and 95%. Specifically, microbiologic eradication r=
ates were 94 to
                     98% for S. pneumoniae, H. influenzae, H. parainfluenza=
e, and M.
                     catarrhalis; 88% for S. aureus; and 100% for K. pneumo=
niae.
                     Eradication rates for atypical pneumonia were 96% for =
Chlamydia and
                     Mycoplasma, and 70% for Legionella. =


                     Levofloxacin is administered IV in a dose of 500 mg by=
 60-minute
                     infusion every 24 hours, or orally as a 250- or 500-mg=
 tablet once daily.
                     It is rapidly and completely absorbed orally (bioavail=
ability about 99%),
                     with peak plasma concentrations attained in 1 to 2 hou=
rs and
                     steady-state levels achieved within 48 hours. Food has=
 little effect on
                     absorption-it prolongs the time to peak concentration =
by about 1 hour
                     and decreases peak concentration by about 14%-so levof=
loxacin can be
                     taken without regard to meals. The drug is 24 to 38% p=
lasma protein
                     bound and is widely distributed into tissues, includin=
g lung tissue and
                     blister fluid (concentration in lung tissue is two- to=
 fivefold higher than
                     plasma concentrations). =


                     Levofloxacin is excreted primarily as unchanged drug i=
n the urine; it
                     undergoes glomerular filtration and proximal tubular s=
ecretion (cimetidine
                     and probenecid reduce levofloxacin clearance by 24% an=
d 35%,
                     respectively). In clinical studies, terminal eliminati=
on half-life was 6 to 8
                     hours (6 hours in females and younger subjects, and 7-=
8 hours in males
                     and older subjects, with differences probably due to r=
enal function
                     status). Patients with creatinine clearance 80 mL/minu=
te or less should
                     have the dosage reduced to avoid accumulation. General=
ly,
                     pharmacokinetics are not influenced by age, sex, race,=
 liver function
                     status, or the occurrence of bacterial infection. =


                     Phototoxic reactions have been rare with levofloxacin =
therapy (occurring
                     in less than 0.1% of patients), but as for all fluoroq=
uinolones, it's a good
                     idea to avoid excessive exposure to sunlight. The drug=
 should be
                     discontinued immediately if a skin eruption occurs. Le=
vofloxacin should
                     be avoided in patients with central nervous system (CN=
S) disorders that
                     predispose to seizures, and diabetics on levofloxacin =
should carefully
                     monitor blood sugar. Although levofloxacin has less af=
finity for cations
                     than do many other fluoroquinolones, patients should b=
e cautioned to
                     take antacids, vitamin and mineral supplements, and su=
cralfate 2 hours
                     before or 2 hours after levofloxacin administration. I=
nteraction studies
                     have shown few or no problems with drugs such as theop=
hylline,
                     warfarin, digoxin, and cyclosporine, although these ag=
ents do interact
                     with other fluoroquinolones. Caution is advised. (Shis=
hido H et al. Drugs.
                     1995[Suppl. 2]:433-435. Information from the manufactu=
rer.) =


                     =A9 1997 VirSci Corporation. All rights reserved.
                     As seen on PharmInfoNet (http://pharminfo.com)

                     Last modified on Tuesday, 11-Mar-97 07:01:56.